ANovel ModellingApproach for Simulating Meltpool Movement in Laser-based Additive Manufacturing

Laser-based additive manufacturing (AM) processes, such as laser powder bed fusion (LPBF), involve the application of a laser beam to selectively melt and solidify powder particles to create three-dimensional objects.These processes are characterized by the dynamic movement of the laser beam over the powder bed, resulting in different geometries.Accurately predicting the thermal behavior within and around the meltpool location during laser beam movement is crucial for optimizing process parameters, predicting material properties, and ensuring structural integrity.Considering the high temperatures involved, the temperature cannot be determined easily through typical experimental means.Thus, the simulation of the temperature development is of key importance as it needs to capture the shape and size of the meltpool and also compute a physically valid temperature distribution within it.The movement of such a meltpool is conventionally simulated via moving heat sources rely on solving transient heat conduction equations, which are computationally expensive as well as complex algorithms for the calibration and movement of such a source.The goal of this work is to showcase a novel and versatile approach for simulating meltpool movement by representing it as a quasi-stationary instantaneous heat source through the projection of temperature.The method involves projecting the temperature field of the meltpool model onto a domain as boundary conditions for a steady-state heat conduction equation in every movement step.The meltpool model chosen is calibrated from experiments and accounts for capillary flow and depth dependent absorption and thus has been already validated in previous research.This model serves as a starting point for implementing an approximation of the heat source movement to be later used for a multi-scale model where information can be upscaled from this approach.Multi-scale models can then be used to capture such fine scale information yet making a computationally feasible model for the entire LPBF process which is then planned to be continued in further publications.The projection approach shows a stable and accurate development of temperatures and is computationally comparable to directly using a source function with parallel processing and comparable to other heat source models in literature.